For the first time, experimental investigations of functional converters of the
electric voltage and current on the base of OEO with RF FODL are fulfilled.
Measurements of its main characteristics show an expedience of its application at
measurement of electrical voltages on large and small values in difficult of access
places with strong external spurious electromagnetic fields. In experimental breadboard of the functional converter of “electrical current–frequency” and “voltage–
frequency” type are, relatively, 3 kHz/A and 1 kHz/V, which allows effective
registration of voltages, currents, and electromagnetic fields in the wide range of
amplitudes with a large dynamic range of 10
3
–10
4 .
In the OEO breadboard of the electric current sensor, the maximal deviations of
OEO frequency were measured. They are Δf ¼ 5.0–10.0 kHz at variation of AC
electric current amplitudes I с ¼ 750–1500 A. A possibility of physical impacts
conversion to the OEO generation frequency is proved theoretically and
experimentally.
As we show, measurements of mechanical displacement during measurement of
two parameters of OEO with RF FODL: the frequency f and signal amplitude,
increases an accuracy and reliability of mechanical displacement measurements.
Double-parameter measurements allows fulfillment of complex compensation
against interference caused, for instance, by a temperature and a pressure affecting
on the optical fiber. Minimal registered level (sensitivity) of such functional converter of “acoustic oscillation–OEO generation frequency” type is approximately
30 mPa.
Main mechanisms of physical quantities into the frequency and into the phase
difference of OEO oscillation are discussed. The functions of OEO frequency for
variations of the light guide length and owing to the light guide mode selection on
the output are analyzed.
For the first time in Russia, we realized the operating structure of the optoelectronic oscillator in the microwave range at the frequency of 8.2 GHz. A possibility is
proved of utilization in OEO with RF FODL in the microwave range of the quantumdimension laser diode with the ultra-wideband modulation bandwidth as the modulated light source, and also the native ultra-wideband photodiode.
The measured experimental frequency function versus the bias current is closed
to the calculated one, and well approximated by the parabolic function. At small bias
currents, the variation slope of the generation frequency is 0.3 MHz/mA. For large
bias currents of QWLD (by 5–8 times), the slope of frequency variations versus the
bias current is 0.003 MHz/mA.
Investigations of frequency functions versus the bias current for different light
guide lengths, formed the fiber-optical system, of 1, 3, 60, 70, and 4500 m is
performed. We proved that the OEO single-frequency mode of generation in the
whole range of bias currents for the filter Q-factor closed to 1000, can be realized at
definite light guide length. So, for instance, at fiber length of 60 m, the singlefrequency mode without jumps occurred in the whole range of bias currents, while at
fiber length of 70 m, the single-mode realized with the jump to adjacent oscillation
type. We made to general conclusion about promising of QWLD application as the
modulated light source in OEO in the microwave range at frequencies 8–15 GHz.
8.6 Conclusions
505
electric voltage and current on the base of OEO with RF FODL are fulfilled.
Measurements of its main characteristics show an expedience of its application at
measurement of electrical voltages on large and small values in difficult of access
places with strong external spurious electromagnetic fields. In experimental breadboard of the functional converter of “electrical current–frequency” and “voltage–
frequency” type are, relatively, 3 kHz/A and 1 kHz/V, which allows effective
registration of voltages, currents, and electromagnetic fields in the wide range of
amplitudes with a large dynamic range of 10
3
–10
4 .
In the OEO breadboard of the electric current sensor, the maximal deviations of
OEO frequency were measured. They are Δf ¼ 5.0–10.0 kHz at variation of AC
electric current amplitudes I с ¼ 750–1500 A. A possibility of physical impacts
conversion to the OEO generation frequency is proved theoretically and
experimentally.
As we show, measurements of mechanical displacement during measurement of
two parameters of OEO with RF FODL: the frequency f and signal amplitude,
increases an accuracy and reliability of mechanical displacement measurements.
Double-parameter measurements allows fulfillment of complex compensation
against interference caused, for instance, by a temperature and a pressure affecting
on the optical fiber. Minimal registered level (sensitivity) of such functional converter of “acoustic oscillation–OEO generation frequency” type is approximately
30 mPa.
Main mechanisms of physical quantities into the frequency and into the phase
difference of OEO oscillation are discussed. The functions of OEO frequency for
variations of the light guide length and owing to the light guide mode selection on
the output are analyzed.
For the first time in Russia, we realized the operating structure of the optoelectronic oscillator in the microwave range at the frequency of 8.2 GHz. A possibility is
proved of utilization in OEO with RF FODL in the microwave range of the quantumdimension laser diode with the ultra-wideband modulation bandwidth as the modulated light source, and also the native ultra-wideband photodiode.
The measured experimental frequency function versus the bias current is closed
to the calculated one, and well approximated by the parabolic function. At small bias
currents, the variation slope of the generation frequency is 0.3 MHz/mA. For large
bias currents of QWLD (by 5–8 times), the slope of frequency variations versus the
bias current is 0.003 MHz/mA.
Investigations of frequency functions versus the bias current for different light
guide lengths, formed the fiber-optical system, of 1, 3, 60, 70, and 4500 m is
performed. We proved that the OEO single-frequency mode of generation in the
whole range of bias currents for the filter Q-factor closed to 1000, can be realized at
definite light guide length. So, for instance, at fiber length of 60 m, the singlefrequency mode without jumps occurred in the whole range of bias currents, while at
fiber length of 70 m, the single-mode realized with the jump to adjacent oscillation
type. We made to general conclusion about promising of QWLD application as the
modulated light source in OEO in the microwave range at frequencies 8–15 GHz.
8.6 Conclusions
505